Vacuum-cushion insert for shoe treads



S. O. MORRISON VACUUM CUSHION INSERT FOR SHOE TREADS Sgpt 28, 1926.

Filed Oct. 10. 1921 taken out and a new insert put in.

l atented Sept. 28, 1926 UNETED STATES PATENT OFFICE.

SAMUEL O. MORRISON, OF UTPER DARBY, PENNSYLVANIA.

vAcUUM-onsnron INSERT roe srron 'rREAns.

y invention relates to vacuum cushion inserts for shoe heels or soles.-

Thepurpose'oit my invention is to supply vacuum cushion inserts for shoe heels or shoe soles that are at once inexpensive, re

sistant to wear and'easily renewable by the A further purpose is to supply an insert having an opening through it terminating in cups at the ends, the insert being reversible end for endand the outer cup with the longitudinal hole through the insert serving 'to make the insert into a pneumatic cushion for the pressure of the step and a vacuum cup to prevent slipping as the shoe is lifted. Further purposes will appear in the spec ification and claims.

I have preferred to illustrate my invention by but one main type, selecting a type that is at once practical, reliable and inexpensive and which atfthe same time well illustrates the principles of my invention.

Figure '1 is a bottom plan showing'my vacuum cushion inserts in a heel.

Figure 2 is a'sectional perspective view of one of my inserts.

Figure 3 is a section taken upon line 3-3 of Figure l, showing'tlie inserts before use.

Figure l corresponds with Figure 3, except that theinserts have been reversed end for end after use. p

Figure 5 is asection corresponding with Figure 3 but showing a modification.

Similar parts in the different figures are designated by the same numerals. Describing the'invention shown, by of illustration and not in limitation :The insert 7, preferably of resilient material such as rubber, has the ends beveled on the outside at 8 and is concaved at 9 between the two bevelled portions The longitudinal passages 10 end in outer and inner cups 11. A number of these inserts are forced into recesses at appropriate points in a heel or sole,

illustrated by heel 12 having openings 13 to.

Application filed October 10; 1921. serial No', 508,847.

conform with the concave surfaces of the inserts. the heel. p

A Washer Hand screw or nail 1 5 with head 16 are conveniently placed in the re 'cess l3 beneath 'the insert 7, the head 16 of the nail or screw seating in the cup 11 ofthe insert. The heel or sole is also preferably of resilient material, such as rubber, and the screw or nail l5 and washer 1d conveniently serve double purpose of supporting the insert and of holding the heel or sole 12 to the shoe (not shown). In Figure 5 there is a slight modification These openings do not pass through in that 12 i's'an outer section of a heel or sole suitably fastened to aninner section 17. The recesses 13 here pass all the way through the material of 12' and the wasl'ie'r 14C may be omitted. p Tlheinsert shown is inexpensive and-effective and is reversible after it has been used. The cushioning eiiect is much more marked, for the quality of rubber used, than in thecase of solid rubberheels and the vacuum eii ect is obtained without sacrificing any of the cushioning benefits. The fasten- 1 ing devices for holding the body or the heel in place are readily accessible through re-- moval of the inserts or maybe applied separately between the inserts and my invent-ion is applicable'to full heels as well as half heels and to leather heels and soles as well as to those made of rubber.

The passages through the middle of the inserts giveroom for them to compress radially when they are inserted, resulting ina radial expansion ofthe entire inserts which is eii'ective tohold them tightly against the 'convex Walls of'the openings and support them againstwithdrawal. 'The same radial pressure of the side walls of the inserts against the openings prevents excessive crowding or the reversed inserts into the openings, so that they hold their positions with less support from the screw or nail heads than would otherwise be the case.

For these reasons I do not require flanges upon the inserts to hold them to their duty and my inserts are distinguished byradial compression as distinguished from axial expansion or distension.

If the inserts be larger than the openings there will be radial compression of the inserts and of the material of the surrounding openings at all times. l Vhether they be of the same size as the openings or not there will be radial expansion of theinserts with pressure in use tending to increase the friction between the side walls of the inserts and those of the openings and to further increase the interlocking in a radial direction between the larger parts of the inserts and the smaller parts of the openings. The friction and interlocking both hold the inserts against withdrawal and with pressure to an increased degree both prevent the inserts from being crowded down full into the openings.

The concavity of the side walls of the inserts in longitudinal section causes a large part of the radial expansion by reason of the axial compression of the inserts to take place outside of and within the outer part of the openings resulting in very satisfactory support of the inserts so as to utilize the outer parts of the insert to a maximum and to tighten the joints between the inserts and the openings.

Support of the inserts from the bottom wall as in Figure 5 of the openings is not objectionable in itself but is merely not as necessary with the present form as it would be if the inserts were convex in longitudinal cross section.

l he inserts can be seated by pressure merely and give good service without any separate holding means other than the mere friction of the side walls. The insert need not be compressed at all when in positioni. e., may be the exact size of the hole. However a slightly larger diameter, providing for slight radial compression when in position, is of advantage. v v

, The passages through the inserts afford easy means of removal through the insertion of any pointed tool.

It is my purpose to include in nclaims all such modifications as would occur to those skilled in the art in view of the disclosure herein and as fall within the reasonable spirit and scope of the claims.

Having thus described my invention, what I claim as new and desire -to secure by Letters Patent is 1. In a shoe tread, a plurality of resilient inserts normally projecting from the tread, forming hollow annular cushion treads, reversible end for end, having bevelled and cupped inner and outer ends and concave circumferential bearing surfaces be tween the ends fitting snugly in recesses in the tread.

2. In a shoe tread, a tread section in combination with a resilient insert normally projecting from the tread section and formmg an annular cushion, reversible end for end and having a central longitudinal passage to give space for an air cushion.

S. In a shoe tread, a tread section in c0mbination with a resilient insert normally projecting beyond the tread forming a hollow annular cushion, reversible end for end, and having bevelled and cupped inner and outer ends, a concave circumferential bearing surface fitting snugly in a recess in the tread, and a central 'longitudinal passage to give additionalspace for an air cushion.

4. In a shoe tread, a tread section having an opening therein flared inwardly and outwardly from the interior in combination with anapertured resilient insert therefor less than onefifth of. the surface area of the tread section, normally projecting beyond 5. In a shoe tread, a tread section and retaining devices therefor, in combination with a plurality of resilient hollow annular cushion inserts, each ofsmall area as cornpared with the tread section, normally projecting beyond the tread section, reversible end for end with bevelled and cupped inner and outer ends and concave circumferential bearing surfaces tightened at the outer portions by pressure, the cups at the outer end formingspace's for air cushions and the 7. In a shoe tread, a tread .section in com bination with a plurality of resilient inserts normally projecting beyond the tread section forming cushion treads, reversible end for end, having bevelled ends and concave circumferential bearing surfaces between the ends fitting snugly in recesses in the tread section, and with central longitudinal passages through the inserts.

8. In a shoe tread, a tread section in combination with a plurality of resilient insert-s therefor having concave circumferential side portions fitting corresponding openings'in the tread and projecting cushion and vacuum cups extending beyond the tread.

SAMUEL o. MORRISON. 

